The idea would be to then balance a tapered oscillator (Gunn Diode ?) cavity and a battery pack w/ a remote photo-switch on a beam held by a suspension fiber and monitor the rotation. I'm thinking one could get some sensitivity multiplication by switching the cavity on and off in time w/ the oscillation frequency of the assembly (easy to do w/ a digital camera) and see if the oscillation amplitude increases w/ time.

I've tried to do searches of multiple types, and have read a few dozen posts, but I still can't answer what seems to be a very simple question, so I'm going to ask.

Has anyone verified that this isn't turning itself into some type of amplified photonic thruster?

The amplification is the Q resonance. The problem is that there are supposed to be no photons whatsoever coming out of the thruster if the EM drive is completely enclosed as a resonant cavity.

If evanescent waves escape from the EM drive through small gaps, the problem is that there can be no amplification of these waves since evanescent waves are exponentially decaying (not resonant) by definition (they are the imaginary solution of the eigenvalue problem, while the resonant modes are the real solutions of the eigenvalue problem of the wave equation).

And even if photons were to escape, how could the performance be better than the one of a photon rocket?

For more on this, please discuss with our resident Photon Rocket expert: @frobnicat

I've tried to do searches of multiple types, and have read a few dozen posts, but I still can't answer what seems to be a very simple question, so I'm going to ask.

Has anyone verified that this isn't turning itself into some type of amplified photonic thruster?

I have suggested something like that. Photons with superluminal momentum or superluminal velocity (a different reference) escaping the cavity via evanescent waves. The references haven't gotten much traction and I've busy with meep so haven't delved into the math. http://wwwsis.lnf.infn.it/pub/INFN-FM-00-04.pdf (See Appendix B, page 15.) People who've looked at the reference get hung up on the causality paradox and can't seem to get past that to look at the math.

My opinion on that is that if the math gives good estimates of the thruster performance, then maybe the paper's author has a valid argument about the causality paradox. Or maybe delve into the tachyon math to see if the paradox really exists in this case.

@Rodal -

Quote

there can be no amplification of these waves since evanescent waves are exponentially decaying (not resonant) by definition

But I think that is the part of the point where the math of superluminal evanescent waves diverge from the classic math. The reference claims to show that the velocity of the wave is a function of the cavity diameter and the gap diameter. If that function of velocity is anything like diameter divided by gap size then the momentum of a single photon could be amplified enormously. Huge momentum from a small number of photons and small number of photons from a small power consumed.

I guess I'll have to set meep aside and delve into MAXIMA just to satisfy myself.

Possibly a stupid question, but was this team using the most productive 'mode/frequency' for the size of their frustum? Having the right mode seems to be crucial to the correct functioning of this device.

Yup! That should do it. Haven't found where I put that Gunn oscillator yet (just had it a couple months ago)

If anyone has one of those speed guns in the drawer I won't ask where you got it .......

Gunn cavities used in speed sensors have a varactor diode and a detector diode inside the cavity; along with the Gunn diode. They don't put out much power - only about 10 - 100 mW; since all the power comes from a small diode and there is no power amp. 24 GHz Gunn horns are also available. One of the interesting effects that low power 10 GHz radiation has is local heating of the skin. If you point a small ( <10 mW ) Gunn horn at the back of your hand you will feel a slight burning sensation; as if the business end of a soldering iron touched your skin.

High power Gunn diodes are available so it is possible to swap out the diode for a high power one. Here are some pictures of a 10 GHz Gunn horn with 3 diodes mounted in it. The label labeled tune connects to the varactor diode and input to the Gunn diode. The detector diode is on the opposite side.

Good luck to the the Eagleworks team. I hope you are able to continue your investigations.

I thought somewhere Dr March had said that GRS's balance sensitivity required an improvement of the thrust signal by 100 percent in order to get successful replication. Did I get that right? I cannot find it now and I have been looking back through the thread for 20 minutes or more. -Anyway; with a deadline of EOM, march; does that mean there is an improved test article about to or in the process of undergoing additional testing at Eagleworks? and can someone link to where that fact (GRS sensitivity limits incapable of detecting current thrust signal level) was posted for reference?

Stormbringer:

The Glenn Research Center (GRC) torque pendulum test rig has a reported sensitivity of ~50 micro-Newton (uN), so we will need a consistent copper frustum thrust performance of at least 100uN to be assured of a successful replication effort at the GRC facility. And no we don't have another test article that performs better than the copper frustum...

BTW, thank you for the PhD title compliment, but I've never earned the title of PhD at any university or other place of higher learning. I can claim a BS in Electrical Engineering from UT at Arlington (1972), and 43 years working in the US aerospace industry in a number of engineering & R&D fields including the last 17 years chasing the experimental verifications of the Mach Effect and now these quantum based thrusters both in my home lab, and at the Eagleworks Lab that I helped create and work in over the last 3.8 years.

The Glenn Research Center (GRC) torque pendulum test rig has a reported sensitivity of ~50 micro-Newton (uN), so we will need a consistent copper frustum thrust performance of at least 100uN to be assured of a successful replication effort at the GRC facility. And no we don't have another test article that performs better than the copper frustum

You may have to resort to the Chinese method, and latch in the most powerful magnetron you can lay hands on.

I've tried to do searches of multiple types, and have read a few dozen posts, but I still can't answer what seems to be a very simple question, so I'm going to ask.

Has anyone verified that this isn't turning itself into some type of amplified photonic thruster?

I have suggested something like that. Photons with superluminal momentum or superluminal velocity (a different reference) escaping the cavity via evanescent waves. The references haven't gotten much traction and I've busy with meep so haven't delved into the math. http://wwwsis.lnf.infn.it/pub/INFN-FM-00-04.pdf (See Appendix B, page 15.) People who've looked at the reference get hung up on the causality paradox and can't seem to get past that to look at the math.

My opinion on that is that if the math gives good estimates of the thruster performance, then maybe the paper's author has a valid argument about the causality paradox. Or maybe delve into the tachyon math to see if the paradox really exists in this case.

@Rodal -

Quote

there can be no amplification of these waves since evanescent waves are exponentially decaying (not resonant) by definition

But I think that is the part of the point where the math of superluminal evanescent waves diverge from the classic math. The reference claims to show that the velocity of the wave is a function of the cavity diameter and the gap diameter. If that function of velocity is anything like diameter divided by gap size then the momentum of a single photon could be amplified enormously. Huge momentum from a small number of photons and small number of photons from a small power consumed.

I guess I'll have to set meep aside and delve into MAXIMA just to satisfy myself.

would deacclerating superluminal waves release Cherenkov radiation? If so; where is the blue glowy stuff? (i like blue glowy stuff. ) Wouldn't a light intensifying camera detect Cherenkov radiation even if there is not enough to be visible to the naked eye?

i know if you remove the IR filter from a regular electronic camera you can turn a normal camera (on a cell phone for example) into a night vision camera. Perhaps there is a way to hack a camera to do the same thing with UV light.

i know if you remove the IR filter from a regular electronic camera you can turn a normal camera (on a cell phone for example) into a night vision camera. Perhaps there is a way to hack a camera to do the same thing with UV light.

No hack required. Most DSLRs should be able to accept a UV filter. Experiment with the settings against a known UV source and you're golden. (Or purplish-blue.)

[Correction, a digital UV filter is a combination of a UV-tuned optical-filter ("black" filter) and an IR blocker. Quirk of digital cameras, apparently. The red channel is also sensitive to UV and the blue channel is also sensitive to IR. D'oh. Nonetheless, no actual camera hacking is required, just suitable filters and a making sure you sample the raw colour channels separately.]

The Glenn Research Center (GRC) torque pendulum test rig has a reported sensitivity of ~50 micro-Newton (uN), so we will need a consistent copper frustum thrust performance of at least 100uN to be assured of a successful replication effort at the GRC facility. And no we don't have another test article that performs better than the copper frustum

You may have to resort to the Chinese method, and latch in the most powerful magnetron you can lay hands on.

Thinker-X:

That possibility has been discussed, but mounting a ~1.0kWe magnetron with a non-fan cooling subsystem and 4.0kVdc power supply on a torque pendulum is not doable at the moment primarily due to time constraints, and yes, the lack of a material budget as well. However this Gunn diode approach being discussed in this forum is a possibility and one that might be doable if we could generate several hundreds watts of wideband RF centered at say 2.45 GHz with just a 28Vdc input.

Hmmm, I read a book by Paul A. LaViolette a while back entitled "Secrets of Antigravity Propulsion" where the author explored in his Figure 8.4 the use of a Gunn diode being amplified by a parametric amplifier that was then fed into a phase conjugate microwave resonator integrated into a propulsion waveguide system developed for a 1970s US black R&D propulsion project. Perhaps it's time to dust off my copy of that book again and take a look-see of how one might at least create the Gunn diode / parametric amplifier portion of this system and then integrate it into our copper frustum.

The Glenn Research Center (GRC) torque pendulum test rig has a reported sensitivity of ~50 micro-Newton (uN), so we will need a consistent copper frustum thrust performance of at least 100uN to be assured of a successful replication effort at the GRC facility. And no we don't have another test article that performs better than the copper frustum

You may have to resort to the Chinese method, and latch in the most powerful magnetron you can lay hands on.

I take it that this is a hanging Pendulum? If these are metal pendulums, is it possible that the magnetic field produced could be tweaking the piviot of the pendulum? probably a dumb question, but I haven't seen any mention of eliminating transient magnetic field generated that could cause such a movement.

Not trying to be obtuse, but sometimesminor things get overlooked. Like a loose cable at CERN.

@aero is using MIT's Finite Difference computer code MEEP to calculate the force produced by evanescent waves escaping from the EM Drive and interacting with the stainless steel vacuum chamber. This work is in progress.Last I heard. my understanding is that it was a 2-dimensional model (because it is a Finite Difference model in space and time, hence takes very long computer running times). The 2-D model simulates the EM Drive as a flat surface with a trapezium for boundaries, and the cylindrical vacuum chamber is being modeled as a flat surface with a rectangle for boundaries.

I don't recall whether the relative permeability used in that analysis for the 304L StSt vacuum chamber material was given.

The experiments performed in China and the UK were not performed inside a vacuum chamber.

Actually the Hafnium one was replicated and DARPA concluded it was real. This was not widely publicised and there was political opposition to it. However, for a variety of interesting reasons, it never went forward (main issue being expense plus lack,of a chain reaction). Work continues though.

Possibly a stupid question, but was this team using the most productive 'mode/frequency' for the size of their frustum? Having the right mode seems to be crucial to the correct functioning of this device.

Brito et al. did not test a microwave resonator frustum aka EmDrive at that time, their experiment was about testing some particular design of Woodward's MLT (Mach-Lorentz Thruster) involving magnetic coils and capacitors, a former design Pr. Woodward later abandoned in favor of a full solid state design aka MET (Mach-Effect Thruster). Hence no waveguide modes.